Patent GB-839483-A (GB)
Title: Improvements in or relating to the coating of organic polymer substrates
IPC: D06M14/26
Filed: 1957-05-21
Abstract: Polymeric substrates are coated with a chemically dissimilar organic substance which becomes bonded to the substrate, by irradiating the substrate in the substantial absence of oxygen with charged particle radiation of energy between 15 and 50,000 electron volts for a minimum exposure of 0.01 watt-sec. per cm.2 and thereafter, while the effect of the irradiation is still active, contacting the substrate with the dissimilar organic material to form the coating.  The dissimilar material may be a polymer, a monomer or a non-polymerizable compound, preferably chain transfer agents containing active hydrogen or halogen, e.g. chloroform, carbon tetrachloride, triphenylmethane, thiols, secondary alcohols and maleic anhydride; fats and proteins may also be used.  The substrate may be of a natural or synthetic polymer.  The irradiation is preferably carried out at room temperature or below and the effect may be preserved by low temperature or inert atmosphere for a considerable period before the coating step is effected.  The substrate may be earthed.  The coating may be applied by dipping, spraying, brushing or printing. In examples: (1) one side of an uncoated regenerated cellulose film is irradiated with 25 KeV electrons and three minutes later the film is immersed in monomeric vinylidene chloride in the dark for twenty hours at room temperature under nitrogen.  The irradiated side acquires a coating of polyvinylidene chloride which is not extractable with dioxane; (2) a film of polyethylene is irradiated in a vacuum at - 78 DEG  C. with 30 KeV electrons and then immersed in acrylic acid for 18 hours at room temperature, rinsed and dried.  A coating of grafted acrylic acid is formed on the irradiated side which shows improved retention of printing ink.  The coating of polyethylene with glycerol or polyethylene glycol to form a hydrophilic surface, or of nylon fabric with palmitic acid to form a hydrophobic coating are referred to. The invention may be used to fine sizes, finishing agents, antistatic coatings and colouring materials to fibrous organic polymers and fabrics and ship agents and waterproofing layers to regenerated cellulose film.ALSO:Fibrous natural or synthetic organic materials are chemically bonded to substances such as sizes, finishing agents, antistatic coatings and colouring materials by irradiating the fibrous material in the substantial absence of oxygen with charged particle radiation of energy between 15 and 50,000 electron volts for a minimum exposure of 0.01 watt-sec. per cm.2 and thereafter, while the effect of the radiation is still active, contacting the substrate with the substance to be bonded thereto. The irradiation is preferably carried out at room temperature or below and the effect may be preserved by low temperature or an inert atmosphere for a considerable period before the coating step is effected.  The formation of a hydrophobic coating on nylon fabric by contacting the irradiated fabric with palmitic acid is referred to.ALSO:Polymeric substrates are coated with a chemically dissimilar organic substance which becomes bonded to the substrate, by irradiating the substrate in the substantial absence of oxygen with charged particle radiation of energy between 15 and 50,000 electron volts for a minimum exposure of 0.01 watt-sec. per cm2, and thereafter, while the effect of the radiation is still active, contacting the substrate with a dissimilar organic material to form the coating.  The dissimilar material may be a polymer, a monomer or a non-polymerizable compound, preferably chain transfer agents containing active hydrogen or halogen, e.g. chloroform, carbon tetrachloride, triphenylmethane, thiols, secondary alcohols and maleic anhydride.  The substrate may be of a natural or synthetic polymer.  The irradiation is preferably carried out at room temperature or below and the effect may be preserved by low temperature or inert atmosphere for a considerable period before the coating step is effected.  In examples: (1) one side of an uncoated regenerated cellulose film is irradiated with 25 Ke V electrons and three minutes later the film is immersed in monomeric vinylidene chloride in the dark for twenty hours at room temperature under nitrogen.  The irradiated side acquires a coating of polyvinylidene chloride which is not extractable with dioxane; (2) a film of polyethylene is irradiated in a vacuum at - 78 DEG  C. with 30 Ke V electrons and then immersed in acrylic acid for 18 hours at room temperature, rinsed and dried.  A coating of grafted acrylic acid is formed on the irradiated side which shows improved retention of printing ink. The coating of polyethylene with glycerol or polyethylene glycol to form a hydrophilic surface, or of nylon fabric to form a hydrophobic coating are referred to.  The invention may be used to fix sizes, finishing agents, antistatic coatings and colouring materials to fibrous organic polymers and fabrics and ship agents and waterproofing layers to regenerated cellulose film.